The newly announced MPR - Magnetic Probe Rack is the perfect product for anyone with an existing Apex or those just now picking one up. The MPR has four locations for probes so customers can rig up their pH, ORP, salinity, and temperature probes. And, it is the only probe holder on the market that has a hole large enough to accept the Apex temperature probe from the top.
The magnets are incredibly strong and will easily hold the MPR to the side of thickest of sumps (up to at least 1/2"). It is stylishly designed and priced on par with other probe holders on the market