Sealand's basic economy model, the 960 Series of SaniPotties is not as sophisticated as their 970 Series counterparts.
The SaniPottie 960 Series is a traditional dual tank portable toilet with a manual bellows-pump flushing mechanism. Push down on the the top of the bellows mechanism (located at the top, rear of the toilet) several times to flush.
Unlike the 970 Series, these 960 series toilets have a slightly textured matte finish and no pour spout for manual emptying. The emptying port is located at the bottom rear of the holding tank, rather than on top. There is no latching seat lid, pressure relief valve, or tank level indicator in the holding tank.

As is typical for many portable toilets, the SaniPottie 960s come with either small or large waste tanks. The 962/964 models can hold 2.6 gallons of waste, and the 965 models hold 5.0 gallons. The upper portion of the toilet, including the flush water tank, is identical on both toilets.

Each size of SaniPottie 960 toilet is offered in two models for emptying:
Standard models are emptied by carrying the holding tank base (with integral handle) to a disposal facility, removing the tank cap, and pouring out the contents.
MSD models feature a molded-in 1-1/2" hose port for dockside pump-out without having to move the toilet. (The MSD fitting includes a 5/8" hose port for a tank vent.)
Typically, the MSD toilets are "hard plumbed" with a user supplied 1-1/2" hose being connected to a pump-out deck fitting, and the vent hose to a small thru-hull fitting. If desired, the hose may be connected to a larger holding tank via an auxiliary manual or electric pump.
Like the Standard models, MSD models can also be emptied via the rear drain opening, should you ever need to carry the holding tank to a disposal facility.

Note that while most of the 960 Series toilets come with mounting brackets over which side latches lock the toilets firmly in place, some do not,.
For those who do not need mounting brakets, the 962 model (2.5 gallon Standard only) toilets do not include them.

2.6 gal flush water supply tank with vacuum vent (all models)
High density polyethylene construction withstands marine environment
Scratch-concealing matte finish looks new for years
Offered in two colors - parchment or platinum
Lift-up seat with lid
Easy disposal via opening port (Standard models); 1-1/2" hose connection (MSD models)
Simple to winterize and maintain. All parts and seals are user replaceable
Two-year limited warranty
2.5 gal models measure 12-1/2"H x 14-1/2"W x 16-1/2"Deep
5.0 gal models measure 15-1/2"H x 14-1/2"W x 16-1/2"Deep


Heavy on the technical side...

How to Select a Portable Toilet
All the portable toilets sold are dual tank models - with separate tanks to hold clean flushing water, and a lower holding tank to contain waste. Flushing portable toilets are designed to provide clean bowls and provide a more home-like experience. During disposal, the tanks are separated, and the holding tank taken to a disposal facility for emptying. Some models offer the option to permanently, or semi-permanently, hard plumb the toilet to a traditional pump-out deck fitting.
It is worth noting that the holding tanks of modern protable toilets have O-ring or gasket seals at every opening which keep waste where it belongs, and virtually eliminate odor problems.

Portable toilets are typically offered in two main versions shorter models with 2-1/2 gallon holding tanks, and taller models with 5 gallon holding tanks.
5 gallon models take up more space, but their higher seat level make them more comfortable for most users. Additionally, 5 gallon tanks have the capacity to go longer between emptying and to accommodate larger crews.
2-1/2 gallon models are shorter, making them easier to stow in cramped boats and RVs. ALL portable toilets have completely sealed holding tanks (you have to be able to carry them), so they can actually be stowed in two pieces when not in use, if desired. This feature makes the 2-1/2 gallon models especially adaptable to the smallest of boats.
By way of reference, houshold toilets typically have a 14-1/2" bowl height, with "comfort height" bowls being about 16-1/2".

A second distinguihing feature among portable toilets is the variety of flushing mechanisms available.
Traditional models have a small hand-operated flushing pump. Some models have accumulator-style flush water tanks which are pre-pressurized and then are good for powering several flushes without additional pumping. Still other models have battery powered electric pumps to do the flushing.
Depending on the amount of water used per flush, 2.5 gallon holding tank models are typically marketed as being good for 20 to 30 uses between emptying, while 5 gallon models can handle 40 to 50 uses.

Additionally, there are a variety of seat styles, colors, design styles, and special features such as pour spouts or tank level indicators available.