Dolphin 6-Lane Stopwatch System - 3 Watches Per Lane horsepower_10 HP It includes the o-ring

It includes the o-ring

Be sure to verify that the tube replacement was due to wear and not an outside contributing factor that could shorten the tube's life

Two (2) Stainless Steel lock washers

This is an Aquador Winter Skimmer Lid Kit for aboeground Hayward SP1090 skimmers

The Linak brand batteries are identifiable by the metal tabs on the bottom of the battery

Dolphin 6-Lane Stopwatch System - 3 Watches Per Lane horsepower_10 HP It includes the o-ringThis is a Dolphin Wireless 6 Lane Stopwatch System with 3 Watches Per Lane. The Dolphin System provides wireless swimming stopwatch style timing for swimming competitions. Each Dolphin system includes the specified number of stopwatches, a base unit, starter unit, and Dolphin software. It significantly reduces the amount of effort required to run a meet and manage data. By transferring all timing data wirelessly, the system has improved accuracy