Ryobi Trimmer

Model#  RY253SS    RY4CSS is the 4cycle   Home Depot
https://www.partstree.com/models/ry-253-ss-090333030-ryobi-string-trimmer-rev-02-2018-02/

Serial#

Plug # L7RTC

Upper Boom HM308470060

Carburetor 
Part# 307160001
fits RY251PH RY252CS RY253SS RY254BC

String Trimmer
090333030
https://www.partstree.com/search/?type=model&term=ry253ss+ryobi+25cc+string+trimmer

Trimmer Head 
Part# 311759014

Shaft 
Part#

Hedge Shears
Part# MFT261-HEDG

Pole (Chain) Saw
Part# RYPRN33

Pole surface Blower
Model# RXB01

Pole Leaf Blower
Part# Ryaxa22

Roto Tiller
Part# AqTT04G
or
ACT05